This invention relates to circularly polarized antennas and more particularly to circularly polarized antennas for use in FM radio or in television broadcasting where the antennas are mounted to the sides of a support mast or tower capable of supporting other antenna systems for other stations or channels. This invention more particularly relates to an antenna which when mounted on this mast or tower radiates in an omnidirectional pattern about the tower such that when this tower is erected in the center of a city, for example, substantially equal coverage is provided about the city. The problem of equal coverage about the tower becomes increasingly difficult as the diameter of the tower becomes largerr with attendant cloverleaf radiation patterns. These tower diameters tend to become fairly large if the tower supports many antenna systems for a plurality of broadcasters. The problem becomes increasingly difficult when this omnidirectional pattern is in the circularly polarized mode.
Although horizontally polarized television broadcasting has been almost exclusively used in the USA, it appears from some recent test results, that circularly polarized broadcasting might well greatly improve television reception both in large metropolitan areas and in fringe areas. It is highly desirable in fringe areas to provide a circularly polarized omnidirectional antenna suitable for television broadcasting and particularly suitable for broadcasting at frequencies as low as 50 MHz where the percentage bandwidth is quite large.